The invention concerns a lighting device which is arranged on motor vehicles and/or in interiors of motor vehicles.
In interiors of motor vehicles are provided a large number of lighting devices, for example the general compartment lighting, ambient lighting, vanity mirror lighting, boot lighting, ashtray lighting and in recent times also lights in the exterior region of the door in order to show the user the way into the vehicle. The light sources or lighting means used in the lamps are relatively space-consuming and must be made exchangeable.
It is the object of the invention to provide a lighting device for mounting in motor vehicles which is space-saving and which has a long life.
This object is achieved according to the invention by the characteristics of the main claim.
Due to the fact that the lighting device comprises an electroluminescent layer assembly comprising at least one first electrode layer, a dielectric layer, an electroluminescent luminous layer and a transparent second electrode layer, wherein the electroluminescent layer assembly is arranged on a support and/or in a frame and the electrode layers are connected to an a.c. voltage control device, a space-saving possibility for a lighting device having many possible uses is provided. The electroluminescent layer assembly can be applied to the support by thick film technology by screen printing or by thin film technology, or it can be constructed separately as a luminous film.
It is particularly advantageous if the a.c. voltage control device is arranged on a printed circuit board which is connected to the support and/or simultaneously constructed as the support for the electroluminescent layer assembly, hence a compact unit is formed which can be clipped in suitable receptacles or used elsewhere.
Due to the measures indicated in the subsidiary claims, advantageous developments and improvements are possible.
The lighting device can be made in any size and it is possible to apply the electroluminescent layer assembly or the luminous film to a flexible support, so that adaptation to the contour of the vehicle is possible even with lamps of large surface area. The electrical control device can in this case in spite of a change of capacitance of the film on account of its geometry be adapted in such a way that the desired shade of colour and the desired intensity of emitted radiation are obtained. If wanted, control of the intensity of the emitted radiation can be performed, as a result of which the ambient brightness can also be included and as a result of which a decrease in brightness on account of the service life can be compensated.
The lighting device used can, as already stated above, be used for the most varied lighting purposes, and it can also be used to illuminate signs in the vehicle from behind, which is particularly an advantage for transport vehicles.